cyberstrikeus 9.3.5 Set SSH MaxAuthTries to 4 or Less (Scored)
Profile Applicability
- Level 1
Description
The MaxAuthTries parameter specifies the maximum number of authentication attempts permitted per connection. When the login failure count reaches half the number, error messages will be written to the syslog file detailing the login failure.
Rationale
Setting the MaxAuthTries parameter to a low number will minimize the risk of successful brute force attacks to the SSH server. While the recommended setting is 4, it is set the number based on site policy.
Audit Procedure
Using Command Line
To verify the correct SSH setting, run the following command and verify that the output is as shown:
grep "^MaxAuthTries" /etc/ssh/sshd_config
Expected Result
MaxAuthTries 4
Remediation
Using Command Line
Edit the /etc/ssh/sshd_config file to set the parameter as follows:
MaxAuthTries 4
Default Value
MaxAuthTries 6
References
- CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0
Profile
Level 1 - Scored